Method for applying new tread material to tires



June 2 4, 1947. T. P. BACON, JR 2,422,652

METHOD FOR APPLYING NEW TREAD MATERIAL TO TIRES Filed Dec 7, 1942 4 Sheets-Sheet 1 IN VEN TOR. Two/mas 5A CON, JR

June 24, 1947. T. P. BACON, JR 2,422,652

METHOD FOR APPLYING NEW TREAD M TERIA TO TIRES' Filed Dec. 7, 1942 4 Sheet-Sheet 2 INVENTOR. THO/1A s P BACON, JR

4 sn eis-sheet 3 IN VEN TOR.

June 24, 1947. 1'. P. BACON, JR

METHOD FOR APPLYING NEW TREAD MATERIAL TO TIRES Filed Dec. 7, 1942 0M. 5 I m OHH ETIL-r rt. 0 Q o o O O CO 1 a o 2 5 o 7 THOMA s P 54 CON,.]R w/0&2,

June 24, 1947. T, P, BACON, JR 2,422,652

METHOD FOR APPLYING NEW TREAD MATERIAL TO TIRES INVENTOR. THoMAs I. BACON, JR.

Patented June 24, 1947 FQR APPLYING NEW TREAD MATERHAL T THREE) Thomas 1?. Bacon, 51:, Dakland, Calif.

Application December 7, 1942, Serial N 0. 4 68.320

(Cl. 154l l) 2 Siaims.

This invention relates to a method and device for applying new tread material to tires.

An object ofthe'invention is to provide a method whereby new tread material, in the form of so-called carnelback can be so applied to the periphery of a tire that it is spread uniformly and securely across the entire tread width and all around the periphery of the tire, and is held there under suitable tension. The method provides for the applying of the carnelback on an inflated tire by suitable rolling action while the tread surface of the tire is flattened to the full width of the c-amelback at the portion where the camelback is applied under pressure, and the method also provides for accurate balancing of the tire before, during and after the application of the new tread material. The result is a tire with semi-cured rubber tread material held all around its tread periphery under suitable transverse and circumferential tension, and ready to be suitably cured to form the tread on the tire. This method may be employed in connection with new tires, as well as in' retreading or recapping,

as the case may be.

Another object of the invention is to rovide a method whereby a strip of tread material can be quickly and efficiently attached to the periphery of a tire; the tire being inflated. and truly bal anced, the camelback being fed tangentially to one portion of the tire periphery at a time while the tire is rotated until the entire periphery of the tire is covered by the c'arnelbaclc; the tread surface of the tire being transversely flattened only where the camelback is tangentially applied to the tire so that the camelbacl; is applied to a hat surface of the tire which is allowed subsequently to expand under the force of inflation, thereby holdin the camelbacl; under tension, both transversely and circumferentially; the camelback on the tire thus prepared is thereafter cured in any suitable manner to form the traction surface of the tire. V

Another object of the invention is to prs viu a method which permits the convenient balancing of the tire so that it is truly balanced when the new tread material is applied to its periphery.

Another object of this invention is to provide a method for applying new tread material to tires which is highly useful and simple construc tion. Convenience of arrangement, lightness and comparative inexpense ofmanufacture are further objects which have been borne in mind in the production and development of the invention.

Other objects of the invention together with the foregoing will be set forth in the following description of the preferred method, and the preferred embodiment of means for practicing the same, which is illustrated in the drawings accompanying and forming part of the specification. It is to be understood that I do not limit myself to the embodiment disclosed in said description and the drawings as I may adopt variations of my preferred forms within the scope of my invention.

The invention is clearly illustrated in the accompanying drawings, wherein:

Fig. 1 is a cross section of the carcass of the tire, the tread surface of which is conveniently prepared for receiving the new rubber.

Fig. 2 is a sectional view of the tire, showing a smaller strip of new rubber applied to it for the purpose of balancing it.

Fig. 3 is a sectional view of the tire, showing somewhat diagrammatically the flattening of the tire at the point where the camelback is applied to the periphery under flattening pressure.

Fig. 4 is'a diagrammatic side View, showing the feeding and-application of the camelbaclg 'to the tire periphery.

Fig. 5 is a 'front'view of said apparatus.

Fig. 6 is aside View of an apparatus for balancing the tire and for applying the oamelback to the tire.

Fig. 7 is a detailed view of a tire rim on which the tire is supported, showing the balancing and journal devices in the rim.

Fig. 8 is a fragmental iew of a modified arrangernent of the pressure roller supported in my apparatus.

Fig. 9 is a fragmental view or" a modified arrangement for the adjustment of the tire relatively to the pressure roller. s

Fig. 10 is a modified forrn of my apparatus.

Fig. 11 is a detail view of the su p ng ro1l-. ers of said modified form, and

Fig. 12 is a fragmental view showi g the deflection measuring device on the apparatus.

The herein method is adapted to be used in. connection with tires where the accurate balancing of the tires is of importance. Such balancing at the present is particularly importantin connection with airplane tires, which byrea son of the transverse curvature of their traction surface present the additional problem of applying the new tread material smoothly acrossth'eentire traction surface and also all around the tire periphery under proper tension, In my method, the tire is first bufled around its peripher y so as to be suitably roughened to receive the tread rubber. After the tire is thus prepared it is tested for balance by supporting it on supports of very small frictional resistance, and is then balanced by applying suitable pieces of tread rubber to such parts of its traction surfaces which may require this added mass for the accurate balance of the tire. Then suitable cement is applied to the roughened periphery of the tire. The tire is provided with the usual inner tube, mounted on a rim and is inflated. Then camelback is applied at one portion of the tire periphery under' such pressure that the tire periphery is transversely flattened for a substantial fiat surface contact with the camelback. Then this pressure point is circumferentially shifted on the the periphery in such a manner as to gradually wrap the camelback around the tire periphery, always keeping the respective portion of the tire Where the camelback is fed to it in flattened condition. The remaining portions of the tire periphery are permittedto assume their substantially normal position under inflation. The'camelback is fed substantially tangentially to the tire periphery and the only portion of the tire periphery which is flattened is the place where the camelback is fed thereunto. In other words, at the transverse line where the portion of the camelback first contacts the tire periphery, the contact is made under pressure suflicient to flatten the tread surface of the tire. The pressure is applied externally upon the camelback and against the in-- ternal pressure of the tire; The area of flattening is shifted circumferentially around the periphery of the tire at the rate the camelback is applied and'the remaining areas of the'tire are permitted to round out under the force of inflation. After the camelback is applied all around the tire, the tire' is again tested and balanced by additional rubber diametrically opposite the heaviest unbalanced parts.

The apparatus for carrying out the above method'includes a frame formed by a pair'of standards IBspaced from each other and supported on any suitable base H. In the present form, the standards are openframes having upwardly converging sides, at the .apex of which is a'journal l8 in which is mounted a pressure roller! 9 transversely between the frames l 6. Spaced from the journal I& to a distance greaterthan the largest tire that may be handled in the apparatus are knife-edge balancing rails =2l. These rails 2| are parallel. There is a rail 2l in .each frame extending substantially at right angles to the axis of the roller IS. The knife-edge of each of the rails 2| is its upper horizontal edge so that a tire with suitable supports may be balanced thereon. It is to be noted that each rail 2! is of sufficient length'to allow considerable rolling and play of the tire in the apparatus for the purpose of determining the balance of the tire. I

A tire 22 is suitably prepared, and then mounted on asuitable rim 23, which in the present illustration is a regular curing rim of the type having flanges extending up on the sides of the tire to about the widest portion of thetire. Inside of this'curing rim23 are provided a pair of spiders 24 spaced from each other axially with respect to the rim 23. The arms or webs ofthe spiders 24'intersect each otherat the axis of the rim 23. A central hub 26 is formed in'each of said spiders 24. -A- shaft 21 extends through the hubs 26 of thespiders 24. The outside ends of the arms of the spiders 24 are provided with arcuate shoes 28 which conform to and suitably engage'the inner surface of the rim 23. The outer ends of the the lateral tilting of the tire.

shaft 2'! are formed into balancing pins 29 of comparatively small diameter. The length of the shaft 26 is so related to the distance between the frame members 16 that the balancing pins 29 of the shaft 27 rest and ride upon the upper knife edges of the opposite rails 2|.

The roller l9 may be so mounted in the frames is as to be movable under pressure against the top of the tire 22. In the present preferred form, however, means are provided for pushing the tire up against the roller l9 to apply the necessary flattening pressure and also to suitably align and center the tire with respect to the roller It. For this purpose, a pair of spaced pressure rollers 3| are supported on arms 32 transversely of the tire periphery and so spaced as to engage the tire periphery and hold the tire accurately centered against the top roller 19. The supporting arms 32 for these rollers 3! are pivotally joined to a sliding block 33, which latter in turn is guided in a vertical guide bracket 36 on a path which is in alignment with the center of the roller l9. In this illustration the arms 32 are also suitably anchored by an adjustable stay 36 whereby the distance between the rollers 3! may be varied. To accomplish the easy movement of the rollers 3.I against the tire 22 for lifting the tire 22 and for pressing it against the top roller 59, a foot lever 31 is provided. This foot lever 3'5 is pivoted on a bracket 38. One end of this lever 31 is pivoted to the sliding block 33. The other end of this foot lever 37 is provided with a suitable foot pedal 39 so that when the operator steps on the foot pedal 39 that will move the block 33 upwardly, so as to force the rollers 3| against the tire 22. The tire shifts between the rollers 3| until it is properly centered and aligned with the pressure roller l9. Further pushing down of the foot pedal 39 exerts the pressure to press the tire 22 against the top roller I9 with sufficient force to accomplish the desired, flattening of the portion of the tire which is opposite the roller l9. A releasable latch 4! is provided on the base I! and can be swung over the foot lever 31 so as to fasten the foot lever in the depressed position where the tire 22 is flattened against the roller H9. The positions of roller 3! can be changed to accommodate tires of various sizes by adjusting the length of the stay 34. It is understood, however, that the same adjustment when needed might be peT'formed by other devices such as by locking the lever 31 in various depressed positions corresponding to the diameters of the tires treated.

The camelback 42 is usually supplied in a reel which is journaled or supported on a suitable journal bracket 43. This bracket may be supported on a, separate support or the bracket 42 may be extended from the standards N5 of the apparatus. A guide roller 44 is supported on arms 46 on the standards l6 so that it is slightly above but parallel with the center line of the roller l9, and guides the camelback 42 from the reel to and under the roller [9. Then as either the roller I9 or the tire 22 is rotated, the camelback 42 is fed and applied to the periphery of the tire 22; In the present illustration the tire would be rotating during this operation in a counter-clockwise direction, viewing Fig. 6.

'While the rollers 31 normally may be sufiicient to support a tire in a vertical position as it is pressed against the pressure roller l9, yet in some instances it may be necessary to prevent For this purpose a guide 50 is extended inwardly from each side threaded shaft 52.

.ei the .f am it. Qn o ese id s s abiyadi ta e to a a e ir s of ou sizes-as to width. The guides 5%? are so spaced M the opposite sides of the hub or the opposi e sides of the tire, the case may be, are in i hi. l din en a emen th t so as o p the unobstructed liij and lowering of the tire toward and away from the top roller it but prevent sidewise tilting of the tire out of the Vfirtical plane.

In the modified form of the apparatus, shown in: Big; 3, the roller 53 is supported onsliding journal bonesv iii, each of which travels on a The threaded shafts ed with a suitable hai slid ng d p l 5 and, are pro :..%.,:for,facilitating the adjustment. Tl 0. cks, 5,! are guided in guide slots heads 53. In this device pressure can be applied by'evenly adjusting th opposite journal boxes by the rotation oi shafts ther 7 i Y ving the roller 5 9 a inst the periphery of W tire .the required pressure.

In the'modif ecl form of the appa at s shown in Fig. 9 the tire 22 is lifted by vert blocks each or" which. has a jou in its top. The ends of the shaft 2? are 1 supported on the seats iii. Each of these slidi blocks is guided between vertical guides suitably supported on transverse braces the converging sides of the stander transverse balancing rails 2i, which latter in this I form are secured to the outside of the vertical guides 53. When the sliding blocks 56 are low ered to below the level of the top edges of the balancing rails 29, then the pins 29 at the ends of the shaft 21 are permitted to rest and freely roll upon the knifeedges of the 25. After balancing the tire the sliding blocks are raised by turning the screw shaft 6i so as to a; the shaft 2? in said seats 5i, thereby the lifted pressed against the roller simplicity of illustration, the handle 62 is herein for the manual turning of the screw iii, but other suitable means may be used for rotating the screw shaft iii,

In the operation of the apparatus herein described, th tire is provided with an inner tube mounted on the rim 23 with suitable balancing or journal spiders 2 therein. The tire is then inflated. The tire 22 is buffed or rough ened on its periphery. The tire is then allowed to freely roll on its balancing pins 25 on the knife edges of the rails 2i. The free rolling of the tire on the rails 2 i, which are truly horizontal will indicate the heaviest parts of the tire and then small patches or strips of carnelback are cemented on the lighter sides of the tire, until the tire is balanced so that it remains stationary in any position upon the rails 25. Then the inflated tire with cement on its outer periphery, is brought to close proximity of the top roller 59 and the end of the camelback 42 is positioned between the roller i8 and the periphery of the ies tire 22, Then the flattening pressure is applied in the manner heretofore "described so as to flatten the tire against the endof the camelbac-k Then by rotating the tire, orby rotating the roller E9, the periphery of the tire 22 is successively. brought into pressure contact with the .amelback d2 under-the roller id. This operaion is continued untilthe entire periphery of he the is wrappedinto the strip of camelba ck Then the camelback i2 is suitably cut so its ends on. thetire are joined. The tire on is again lower d onto the balancing rails iii in the event of any unbalanced portion the same is suitably corrected by applying some rubhe at points'di metrically opposite to the heavportions or tire periphery. The tire thus 1. epared is placed in any suitable mold for the curing of. the camelback so as to vulcanize the sam integrallyto the tire periphery into the desired traction surface.

In the mo :fied embodiment of my invention show- Figs. 19 and 11, another form of support for the tire 22. in the apparatus is provided for hoiding the tire in a balanced position. The standards it in this form are preferably supported on a deeper base lit, in which is a central hydraulic iii; of the usual type. On this ram are supported pair of lateral arms 68 which extend substantially transversely and on an upncline between the standards H3. The end r ch arm is forlged, the prongs 69 of which end on an incline into the space between the standa d it and toward the respective opposite standards iii on each side of the tire. In other words, the prongs 59 on each arm s are divergent and are an upward incline, but the sets of prongs 553 on the opposite arms t8 converge toward each other. This is accomplished by bendthe end of each arm is toward the position of the tire 22 between the standards l6. On each prong 69 is a supporting roller ii. The tire 22 wedges itself between the rollers 71 l but by reason of the substantially tangential contact of the shoulders or sides of the tire 22 with the rollers l'i, the tire 22 can be easily rotated. As the tire 22 is rotated, it rotates the rollers i i, yet it is securely supported in the opposite roller forks. This opposite fork support of the tire will maintain the tire in substantially vertical position. The tire is raised and lowered by the raising and lowering of the ram 5'5, the pressure in which latter is controlled and manipulated in any suitable manner not shown.

In this form, I also illustrate a use of the device for determining and marking the deflection line on the tire 22. Tires are usually so inflated that under a specified load the tire will be compressed to a given percentage of its height. In order to fa litate the inflation of such tires to the desired pressure, the percentage of specified deflection is indicated by a circular marking around the tire, and the tire is inflated under a given load to be flattened to the deflection mark indicated on the tire. The marking and measuring a specified percentage of deflection involved in the past a separate and complicated operation. In apparatus, I provide a scale 12 which is frictionally held in its adjusted positions in a guide 13 at the apex of one of the standards It such position that the scale 12 is in registry and parallel to the vertical diameter of the ssure roller 58 and of the tire 22. The lower end of the scale i2 is bent inwardly to form an indicator id for the rim flange position of the tire 2'2. Inasmuch as the desired deflection is specified usually in percentages, the marking of the tire is accomplished in my apparatus by quickly calculating the percentage on the scale 12. The tire is first brought into contact with the roller I9 without compressing it. Then the scale 12 is pushed in its guide 13 to a position where the indicator I4 is aligned with the rim 23 of the tire. Then a reading is taken on the scale 12 to the lowest point of the roller l9, which shows the expanded height of the tire. Then from that the desired percentage of deflection is calculated and deducted. The normal inflated vertical distance from the rim flange to the supporting surface of the tire is considered in present specifications for airplane tires for landing wheels, as the distance equivalent to 100% deflection. The specifications under a normal load specify a vertical deflection at the proper pressure for said load of 35%. After the 35% of said distance as shown on the scale is determined, the scale 12 is pushed I up toward the roller [9 so as to deduct this 35% from the scale length below said roller I9, namely, so that the marker 14 assumes a position with the indicator M 35% above its previous position.

Then the tire 22 is pressed against the roller l9 until the rim flange 23 is in alignment with the indicator 14. In this last position the tire is compressed to the desired 35% deflection. Then by applying paint, chalk or the like to the shoulder or side of the tire at about the point where it turns to its flattened tread surface at the roller l9, and then by rotating the tire 360", an accurate circular marking is obtained. Finally this markin is covered with indelible paint or the like and forms the permanent desired deflection marking on the tire.

I claim:

1. The method of covering the traction periphery of a pneumatic tire with a strip of tread material, which comprises the inflating of the tire, the supporting of the inflated tire on a balancing axis central to said tire, the engaging of the portion of the tire below said axis and the lifting of said tire against a surface so as to flatten the portion of the tire engaged at said surface transversely to about the width of said strip, and simultaneously feeding said strip between said surface and said tire at said flattened portion and rotating said tire until the entire traction periphery is covered by said strip.

2. The method of covering the traction periphery of a pneumatic tire with a strip of tread material, which comprises the inflating of the tire, the supporting of the inflated tire on a balancing axis central to said tire, rotatively engaging the portion of the tire below said axis and the lifting of said tire against a rotatable surface so as to flatten the portion of the tire engaged at said rotatable surface transversely to about the width of said strip, and simultaneously feeding said strip between said surface and said tire at said flattened portion and rotating said tire until the entire traction periphery is covered by said strip.

THOMAS P. BACON, JR.

REFERENCE S CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,257,898 Breth Oct. 7, 1941 1,614,892 McGovern Jan. 18, 1927 2,282,580 Hawkinson May 12, 1942 1,209,161 Hoyt Dec. 19, 1916 2,009,643 Woock July 30, 1935 

